Shannon Maxwell speaks proudly of her three children, now ages 11 to 20, whose lives completely changed when their father, Marine Lt. Col. Tim Maxwell, was severely wounded by a mortar attack on his third deployment to Iraq.

Oldest daughter Alexis, then 11, was forced into independence, caring for herself and her younger siblings while Shannon spent time at the hospital with Tim.

And the younger children were partly raised by relatives, neighbors and friends so Shannon could help Tim focus on recovery.

Today, Alexis is a student at Texas A&M,­ studying kinesiology so she can work with wounded troops. Eric wants to be a Marine, and Cassidy, at 11, “is wonderful, a self-advocate who does more at home” than others her age, their mother said.

But the path has been anything but smooth, she said, and outside the bubble of a military base, the family found obstacles ranging from finding therapists who understood their situation to getting teachers to grasp why the kids’ school work or behavior might be affected.

The Maxwells are among the nearly 2 million children of troops affected by the wars in Iraq and Afghanistan. Like many, they have displayed resilience in the face of difficulties and look at life with a can-do spirit. But they also face challenges, including finding mental health treatment, support and guidance tailored to their needs.

A new publication by Princeton University and the Brookings Institution examines the lives of military children like the Maxwells and makes recommendations to provide services to cultivate future success.

The needs are so great, researchers say, that a national strategy should be developed to educate communities on how to support these kids, to screen them for risk and help those already in trouble, according to the report, “The Future of Children: Military Children and Families.”

“Effective programs must interact within health care settings but also in schools and churches, youth organizations, law enforcement and the judiciary and veterans organizations to create informed communities,” said Dr. Stephen Cozza, a psychiatrist at the Uniformed Services for the Health Sciences in Bethesda, Md.

Problems facing children affected by war are starting to garner national attention. In July, Child Trends issued a study on the impact of deployment on young children; the National Academies of Sciences have an ongoing effort to study the readjustment needs of military families; and Pulitzer Prize winning journalist David Finkel just published a new book on the impact of war on families.

But 12 years after 9/11, challenges persist, even in communities with large military populations, said social scientists and military family members. One military spouse said that in Fairfax County, Va., outside Washington, D.C., where she lives, her son has been passed between schools and told by professionals that he has “experiences beyond his years” that they aren’t equipped to handle.

“My frustration is the lack of military culture education, even with the licensed professionals,” the mother said.

One step, according to Mary Keller with the Military Child Education Coalition, is to require ongoing professional development among teachers and other professionals who work with military children.

“Development — not a one-shot deal,” Keller said. “The one thing about military families is we can learn from them and we can learn for them and together, we better serve all kids.”

But officials agreed that additional programs aren’t necessarily the answer. In a tight budget climate, quality is better than quantity, according to Brig. Gen. Russell Sanborn, director of Marine and Family Programs for the Marine Corps.

“The Corps is evaluating its preventive services and treatments for families and children to decide which ones work and which can be tossed — a review critical to maintaining both readiness and quality of life,” Sanborn said.

Given the multitude of nonprofit organizations, medical groups, youth advocates and military and veterans service organizations, military children should be able to find the help they need. But sound directives, in the form of a national strategy, could help these disparate groups work as a team to more seamlessly support affected children.

Maxwell, who with her husband founded the nonprofit SemperMax to assist wounded personnel and their families, pleaded for national guidance.

“The military has done a good job and some of the nonprofits are filling the gap, but this is not just a government situation,” Maxwell said. “This is something that needs to be put in the broader community. There needs to be an integrated national campaign.”